Medical systems are designed to improve the diagnostic and surgical applications of the medical practitioners. However, due to their medical application, they also have to be safe for both the patient and operator/practitioner. There are international standards such as the IEC/EN standards, and also FDA guidelines that guide on the suggested safety measures needed of the medical system and its accessories. To achieve this safety, it is imperative that both the medical system and its associated accessories meet these safety standards/guidelines. However, the safe use of the medical system and its accessories are also dependent the responsibility of the user in recognizing a defect or disposing of non-sterile/non-safe accessories. Hence, in a particular instance, it is desirable that use of an electrosurgical handpiece be controlled to ensure its safe use. An important application of this principle is to avoid repeated use of the same handpiece. This is especially important in its application to non-ablative surgery, an example of which is described in our co-pending application Ser. No. 11/546,850, filed Oct. 13, 2006, the contents of which are herein incorporated by reference. In this application, which is non-invasive, the appearance of the electrode may not materially change after use, though it becomes non-sterile, and so the possibility exists of the surgeon inadvertently reusing the handpiece with the same electrode on a different patient. This problem can be overcome by making the handpiece disposable, intended for only a single use. But even if sold as a disposable handpiece, there remains the possibility that the handpiece will be reused with the same electrode or with a different electrode, as most handpieces allow electrode replacements.